1. Field of the Invention
The present invention relates to an assembly of an elongated container and a plug therefor such as, for example, an assembly of a vacuum bottle and a plug therefor designed to maintain the desired temperature of contents.
2. Prior Art
A conventional container and plug assembly comprises an elongated container having a closed longitudinal one end and the other longitudinal end and a plug for the container. The container has a receiving space defined at the longitudinal one end for receiving contents such as, for example, hot or cold drinks, and an opening defined at the other longitudinal end. The contents are filled into the receiving space and are discharged therefrom through the opening. An annular ridge having a rounded annular top is formed between the opening and the receiving space and has a circumferential sealing surface defined at a flank of the annular ridge which faces to the opening.
The plug has one and the other axial ends and is threadedly engageable with the container so as to open and close the opening by the axial one end of the plug. An annular sealing member is carried on the other axial end of the plug.
The annular ridge having defined on the flank thereof the circumferential sealing surface is formed at a location spaced from the opening toward the receiving space a predetermined distance sufficient to provide a satisfactory heat insulation. With the opening being closed by the axial one end of the plug, the sealing member carried on the other axial end of the plug is in sealing contact with the circumferential sealing surface on the annular ridge, to thereby provide the heat insulation together with a fluid tightness.
However, in order to bring the sealing member carried on the other axial end of the plug into sealing contact with the circumferential sealing surface on the annular ridge simultaneously with the closure of the opening by the axial one end of the plug, it is required to manufacture the container and the plug so as to accurately position the annular ridge with respect to the opening and so as to accurately position the sealing member with respect to the axial one end of the plug. This inevitably necessitates severe manufacturing tolerances for the container and the plug, resulting in the increase in manufacturing cost of the container and plug assembly.